Important research questions in allergy and related diseases: 3-chronic rhinosinusitis and nasal polyposis - a GALEN study

T cells producing the anti-inflammatory cytokine IL-10 regulate allergen-specific Th2 responses in human airways

BACKGROUND

Murine models suggest a critical functional role for the anti-inflammatory cytokine IL-10 in local regulation of allergic airways inflammation. There is little corresponding information on human airway cells. This study aimed to investigate whether local IL-10 production regulates responses by respiratory mucosal leucocytes isolated from nasal polyps.

MATERIALS AND METHODS

Nasal polyp tissue was harvested from 24 patients sensitised to aeroallergens with chronic rhinitis and polyposis undergoing routine polypectomy. Cells were isolated by matrix proteolysis. Cytokine production by polyp cells was determined by cytometric bead array (CBA) and intracellular cytokine analysis. Surface marker expression by polyp cells was determined by flow cytometry.

RESULTS

Allergen stimulation significantly enhanced production of IL-10, but not IL-5 or IFN-γ by nasal polyp cell suspensions. Under the same conditions, neutralisation of IL-10 significantly increased allergen-specific IL-5 and IFN-γ production by nasal polyp cells. Cell depletion experiments showed that T cells themselves were primarily responsible for IL-10 production or for inducing its production by other cells. Intracellular cytokine staining confirmed production of IL-10 in the absence of IL-2 production by T cells in response to allergen.

CONCLUSION

T cells within the human respiratory mucosa produce IL-10, which is capable of inhibiting pro-inflammatory Th2 and Th1 cytokine production in an antigen-specific fashion.

Defective epithelial barrier in chronic rhinosinusitis: the regulation of tight junctions by IFN-γ and IL-4

BACKGROUND

Chronic rhinosinusitis (CRS) is a common disease with still unclear pathophysiologic mechanisms. Epithelial tight junctions (TJs) have been shown to be involved in different chronic disorders, including bronchial asthma, inflammatory bowel diseases, and skin disorders. The regulation of epithelial barrier function and TJ expression has not been extensively studied in patients with CRS and in the paranasal sinus epithelium thus far.

OBJECTIVE

We sought to elucidate the TJ expression pattern in the epithelium of the sinonasal mucosa and its regulation in patients with CRS.

METHODS

Trans-tissue resistance was measured in biopsy specimens from healthy control subjects and patients with CRS with and without nasal polyps. TJ protein expression was determined by using immunofluorescence, Western blotting, and real-time PCR. Primary epithelial cell cultures from patients with CRS and control subjects were used in air-liquid interface (ALI) cultures for the measurement of transepithelial resistance (TER) and TJ expression. The effect of IFN-γ, IL-4, and IL-17 on ALI cultures was assessed.

RESULTS

A decreased trans-tissue resistance was found in biopsy specimens from patients with CRS with nasal polyps along with an irregular, patchy, and decreased expression of the TJ molecules occludin and zonula occludens 1. TER was reduced in ALI cultures from patients with CRS with nasal polyps. The cytokines IFN-γ and IL-4 decreased TER, whereas IL-17 did not have any influence on epithelial integrity.

CONCLUSION

A defective epithelial barrier was found in patients with CRS with nasal polyps along with a decreased expression of TJ proteins. The disruption of epithelial integrity by IFN-γ and IL-4 in vitro indicates a possible role for these proinflammatory cytokines in the pathogenesis of patients with CRS.

Increased expression of IL-19 in the epithelium of patients with chronic rhinosinusitis and nasal polyps

BACKGROUND

Chronic rhinosinusitis (CRS) is an inflammation of the nose and of the paranasal sinuses. The involvement of the respiratory epithelium in the mechanisms of CRS is poorly understood.

AIMS

Among proteins expressed by nasal epithelial cells in CRS, IL-19 may have key functions. We here aimed to determine the expression and regulation of IL-19.

METHODS

Nasal biopsies from normal subjects (n = 12), subjects with CRS but without nasal polyps (NP) (CRSsNP, n = 12) and with CRS with NP (CRSwNP, n = 15) were collected. Human Asthma Gene Array and real-time PCR were used to evaluate gene expression, western blot analysis and immunohistochemistry for protein expression. Results for IL-19 were confirmed by real-time PCR. The constitutive and stimulated (LPS, TGF β) expression of IL-19 and cell proliferation were evaluated in a nasal epithelial cell line (RPMI 2650).

RESULTS

Human Asthma Gene Array showed an increased IL-19 gene expression in NP from patients with CRS in comparison with normal subjects. Real-time PCR confirmed the IL-19 mRNA up-regulation in patients with CRSwNP and showed an up-regulation of IL-19, at lower extent, in patients with chronic rhinosinusitis without nasal polyps (CRSsNP) in comparison with normal subjects. Western blot analysis confirmed that IL-19 is increased also at protein level in patients with CRSwNP in comparison with normal subjects. In NP, IL-19 is highly expressed in the metaplastic nasal epithelium when compared to normal or hyperplastic epithelium. LPS stimulation increased IL-19 expression, and recombinant IL-19 increased cell proliferation in nasal epithelial cells.

CONCLUSIONS

IL-19 is overexpressed in the epithelium in CRSwNP and increases epithelial cell proliferation.

Fungi linking the pathophysiology of chronic rhinosinusitis with nasal polyps and allergic asthma

The immunologic reaction to fungal stimuli has long been thought to be a contributor to the development of sinonasal disease. We aim to review the role of fungi in upper and lower airway inflammatory diseases. The immune response to fungi in the pathogenicity of specific respiratory inflammatory diseases such as allergic bronchopulmonary aspergillosis and a subtype of CRS known as allergic fungal rhinosinusitis has been relatively well described. Fungi are thought to serve both as immunogenic antigens and as adjuncts to inflammation through protease activity. Development of a recent murine mouse model of asthma bypassing the pre-sensitization of allergen further suggests a broader role for fungi in allergic asthma. The literature is lacking in defining a clear presence of fungi within the inflamed sinus cavity of CRS patients and its potential immunologic effects, as well as the utility of antifungal therapy for CRS management. We will review these data and potential common molecular mechanisms activated by fungi in the common pathway toward upper and lower airway inflammatory pathology.

Comorbidities between nose and skin allergy

PURPOSE OF REVIEW

This review focuses on comorbidities between nose and skin allergies. For this purpose, allergic rhinitis and chronic rhinosinusitis (CRS) were selected as examples of nasal disorders and atopic dermatitis and urticaria as examples of allergic skin disorders and the individual entities of both localizations were evaluated and compared in relation to their prevalence and coincidence, underlying pathophysiological mechanisms, genetic data and shared therapy options.

RECENT FINDINGS

The inter-relationships between atopic dermatitis and allergic rhinitis are the best studied, but even for the other comorbidities it was possible to demonstrate comparable pathomechanisms in addition to a high prevalence and coincidence, particularly in the case of atopically assisted forms. In this context, the interactions of IgE, mast cells and eosinophils play a special role, but genetic issues, the significance of epithelial barrier defects and colonization with Staphylococcus aureus are also important sharing issues.

SUMMARY

Allergic skin disorders such as atopic dermatitis and urticaria are frequently associated with comorbidities of the nose as well as allergic rhinitis and CRS. By contrast, different manifestations of these diseases involve the nose and the skin. These are not separate diseases but are linked by complex and currently unclear/insufficiently defined inter-relationships.

Differential expression of interleukin-32 in chronic rhinosinusitis with and without nasal polyps

BACKGROUND

  Chronic rhinosinusitis (CRS) is a heterogeneous disease characterized by local inflammation of the upper airways and sinuses and is frequently divided into polypoid CRS (CRSwNP) and nonpolypoid CRS (CRSsNP). However, the mechanism of inflammation in CRS has still not been fully elucidated. The aim of the study was to investigate the role of interleukin-32 (IL-32), a recently discovered proinflammatory cytokine, in CRS.

METHODS

  We collected nasal epithelial cells and nasal tissue from patients with CRS and control subjects. We assayed mRNA for IL-32 by real-time PCR and measured IL-32 protein using ELISA, Western blot, and immunohistochemistry.

RESULTS

  The expression of mRNA for IL-32 was elevated in epithelial cells from uncinate tissue from patients with CRSsNP compared with patients with CRSwNP (P < 0.05), control subjects (P=0.06), and epithelial cells from nasal polyp (NP) tissue (P < 0.05). Production of IL-32 was induced by IFN-γ, TNF, and dsRNA in primary airway epithelial cells. In whole-tissue extracts, the expression of IL-32 protein was significantly elevated in patients with CRSwNP compared with patients with CRSsNP and control subjects. Immunohistochemistry data showed that IL-32 was detected in mucosal epithelial cells and inflammatory cells in the lamina propria. Levels of IL-32 were correlated with the levels of CD3 and macrophage mannose receptor in NP tissue. Immunofluorescence data showed IL-32 co-localization with CD3-positive T cells and CD68-positive macrophages in NPs.

CONCLUSION

  Overproduction of IL-32 may be involved in the pathogenesis of CRS, although the role of IL-32 in the inflammation in CRSsNP and CRSwNP may be different.

Increased expression of CC chemokine ligand 18 in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is associated with T(H)2-dominant inflammation, including eosinophilia, which is in contrast to chronic rhinosinusitis (CRS) without nasal polyps (NPs). CC chemokine ligand 18 (CCL18)/pulmonary and activation-regulated chemokine is known to recruit naive T cells, B cells, and immature dendritic cells, as well as to activate fibroblasts. CCL18 is thought to be involved in T(H)2-related inflammatory diseases, including asthma and atopic dermatitis.

OBJECTIVE

The objective of this study was to investigate the expression of CCL18 in patients with CRS.

METHODS

Using NP tissue and uncinate tissue (UT) from control subjects and patients with CRS, we examined the expression of CCL18 mRNA using real-time PCR and measured CCL18 protein using ELISA, Western blotting, and immunofluorescence.

RESULTS

Compared with UT tissue from control subjects, CCL18 mRNA levels were significantly increased in NPs (P < .001) and UT (P < .05) from patients with CRSwNP but not in UT from patients with CRS without NPs. Similarly, CCL18 protein levels were increased in NPs and UT from patients with CRSwNP, and levels were even higher in patients with Samter's triad. Immunohistochemical analysis revealed CCL18 expression in inflammatory cells, and CCL18(+) cell numbers were significantly increased in NPs. Immunofluorescence data showed colocalization of CCL18 in CD68(+)/CD163(+)/macrophage mannose receptor-positive M2 macrophages and tryptase-positive mast cells in NPs. Levels of CCL18 correlated with markers of M2 macrophages but not with tryptase levels, suggesting that M2 macrophages are major CCL18-producing cells in NPs.

CONCLUSION

Overproduction of CCL18 might contribute to the pathogenesis of CRSwNP through its known activities, which include recruitment of lymphocytes and dendritic cells, activation of fibroblasts, and initiation of local inflammation.

Variations in expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in nasal mucosa of aspirin-sensitive versus aspirin-tolerant patients with nasal polyposis

BACKGROUND

Matrix metalloproteinases (MMPs) are key enzymes responsible for extracellular matrix degradation contributing to the progressive histological changes seen in lower airway disease, including asthma. MMP-9 and TIMP-1 have also shown some role in the pathogenesis of chronic rhinosinusitis (CRS) and nasal polyposis (NP).

OBJECTIVE

We aim to determine variability in expression of MMP-9 and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), in sinus tissue from distinct patient populations presenting with nasal polyposis.

METHODS

The expression of MMP-9 and TIMP-1 was investigated in nasal polyp tissue from 6 aspirin-sensitive (AS) and 6 aspirin-tolerant (AT) patients undergoing endoscopic sinus surgery for chronic rhinosinusitis with nasal polyposis (CRSwNP). Sinus mucosa from 6 patients with chronic rhinosinusitis without nasal polyposis (CRSsNP) was used as control. The MMP-9 and TIMP-1 expression was measured using immunofluorescence technique and graded using manual and computerized methods.

RESULTS

Expression of TIMP-1 was significantly reduced in the AS group when compared with both the AT and CRSsNP (control) groups (P < .001). The MMP-9/TIMP-1 ratio was significantly increased in the AS group when compared with other patient groups (P < .001). The MMP- 9 expression was similar between study and control groups.

CONCLUSION

These results support the importance of MMP-9 and TIMP-1 expression in nasal polyp formation. The decreased expression of TIMP-1 in AS patients may promote the effects of MMP-9 expression and thus contribute to tissue remodeling and inflammatory changes. This finding may lead to further understanding of disease severity and resistance to treatment in this group of patients, as well as the pathogenesis of nasal polyps.

NOD-like receptors in the human upper airways: a potential role in nasal polyposis

BACKGROUND

Nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) are newly discovered cytosolic receptors belonging to the pattern-recognition receptor family. They detect various pathogen-associated molecular patterns, triggering an immune response. The knowledge about these receptors, and their role in health and disease, is limited. The aim of the present study was to characterize the expression of NOD1, NOD2, and NALP3 in the human upper airways.

METHODS

Surgical samples were obtained from patients with tonsillar disease (n = 151), hypertrophic adenoids (n = 9), and nasal polyposis (n = 24). Nasal biopsies were obtained from healthy volunteers (n = 10). The expression of NOD1, NOD2, and NALP3 was analyzed using real-time PCR and immunohistochemistry.

RESULTS

Expression of NOD1, NOD2, and NALP3 mRNA and protein were seen in all tissue specimens. The NLR mRNA was found to be higher in nasal polyps than in normal nasal mucosa, and local steroid treatment reduced the NLR expression in polyps. In contrast, tonsillar infection with Streptococcus pyogenes or Haemophilus influenzae did not affect the NLR expression.

CONCLUSIONS

  The present study demonstrates the presence of NLRs in several upper airway tissues and highlights a potential role of NLRs in chronic rhinosinusitis with polyps.

Effect of pulsed ultrasound on chronic rhinosinusitis: a case report

This case report demonstrates that pulsed ultrasound (US), when used for a total of 20 treatment sessions, provided symptom relief to a patient with chronic rhinosinusitis (CRS). A 16-year-old boy with a 12-month history of rhinosinusitis and candidate for sinus surgery was referred for ultrasound therapy. He presented with facial pain/pressure, nasal obstruction, and postnasal drip (total sinusitis score=7). On computed tomographic (CT) scanning, the total opacification of the right maxillary sinus was observed. The ostiomeatal complex was occluded (total CT score=6). Pulsed ultrasound was administered three times a week, every other day. After 10 treatment sessions, his symptoms were resolved with exception of nasal obstruction being mild (total sinusitis score=2). On CT scan, right maxillary sinus showed partial improvement (total CT score=2). After additional 10 treatments, the nasal obstruction was resolved, and follow-up CT scan of his sinuses showed that right maxillary sinus was clear and normal. At 6-month follow-up, the positive effects were maintained and the patient reported no recurrence of symptoms. Twenty sessions of pulsed ultrasound therapy eradicated the CRS and resolved the symptoms.

Is there a role for leukotriene antagonists in the prevention of recurrent nasal polyps?

PURPOSE OF REVIEW

The aim of this review is to provide the current available data for leukotriene receptor antagonists in the treatment of nasal polyps, the use in the postoperative therapy single or as an add-on to standard treatments.

RECENT FINDINGS

Surgical treatment of nasal polyps was refined in the last 30 years by the introduction of functional endoscopic sinus surgery and nasal endoscopy for monitoring nasal polyp patients. As the relapse is the main challenge and as nasal steroids only delay it, a more efficient treatment is needed. Leukotriene antagonists have effects on asthma and allergic rhinitis; preliminary data show some benefits in nasal polyps.

SUMMARY

In the surgery of nasal polyps, recurrence is the main problem. Steroids are the current standard therapy, but the limitations are obvious. The role of leukotrienes in the disorder of nasal polyps is well established now, and with the antagonists available, interest rose in treating nasal polyps. A total of 356 patients took part in several studies involving leukotriene antagonists in the nasal polyp population. Some studies have minor levels of evidence; the data show positive effects for patients in preoperative and postoperative studies and medical treatments. There were benefits as an add-on to steroids and data from allergic rhinitis studies also show possible synergism with antihistamines. There are hints for a positive effect on eosinophil inflammation, clinical symptom scores, nasal airflow, sneezing and postnasal drip. Although some effects are shown, more controlled studies are necessary for reliable data.

Lower sensitivity of nasal polyp fibroblasts to glucocorticoid anti-proliferative effects

BACKGROUND

Treatment with glucocorticoids (GCs) is the cornerstone of nasal polyp (NP) therapy, but some patients respond poorly to them. Fibroblasts are involved in both inflammation and remodelling of NP. We aimed to evaluate whether NP fibroblasts are less sensitive to GCs' anti-proliferative and anti-inflammatory effects, compared to nasal mucosa (NM) fibroblasts.

METHODS

Fibroblasts were obtained from NP (n = 8) from asthmatic patients undergoing endoscopic surgery and NM (n = 8) from patients undergoing nasal corrective surgery. Fibroblasts were stimulated with DMEM at 0.5% or 5% FBS, or TGF-β (5 ng/ml), with or without dexamethasone (10(-11) to 10(-5)M) for different times. Cell proliferation, collagen mRNA expression and IL-6 and IL-8 release were measured.

RESULTS

After 3-days, dexamethasone dose-dependently inhibited proliferation of NM (p < 0.001) but not that of NP fibroblasts. Dexamethasone (10(-6)M) reduced by 25% the proliferation of NM fibroblasts. Dexamethasone also inhibited proliferation of NM (p < 0.01) but not that of NP fibroblasts at 5-days. TGF-β induced collagen-1α1, -1α2, and -3α1 mRNA levels in both NM and NP fibroblasts (p < 0.05), and dexamethasone did not alter TGF-β-induced collagen mRNA levels in either fibroblast type at 24 h. Dexamethasone dose-dependently decreased (p < 0.05) FBS-induced IL-6 and IL-8 release in both NM and NP fibroblasts at 4 h, although at 10(-8)M, dexamethasone inhibited cytokine production in NM (p < 0.05) but not in NP fibroblasts.

CONCLUSIONS

This impaired sensitivity of nasal polyp fibroblasts to in vitro glucocorticoid effects concurs in part with the poor clinical response that these nasal polyp patients show to glucocorticoid treatment.

Rhinosinusitis and asthma: a link for asthma severity

The term rhinosinusitis describes an inflammation of the mucosal lining of the nose and sinuses; however, recent evidence points to the need to differentiate patients with chronic rhinosinusitis without nasal polyps from those with nasal polyps. Asthma comorbidity is especially common in nasal polyp disease and may be associated with aspirin-exacerbated respiratory disease. Of interest, asthma comorbidity is uncommon in some parts of the world but common in others. A further analysis of the inflammatory patterns also revealed that nasal polyps do not represent one single entity; interleukin (IL)-5-positive nasal polyps can be differentiated from IL-5-negative forms by different inflammatory patterns (predominance of eosinophils vs neutrophils). Staphylococcus aureus superantigens frequently colonize IL-5-positive nasal polyps and may amplify the eosinophilic inflammation, induce a polyclonal local IgE formation, and increase the risk of asthma comorbidity. Recent findings in severe asthma patients confirm the role of superantigens in lower airway disease.

Trends on rhinosinusitis diagnosis and treatment

A growing interest in rhinosinusitis in recent years resulted in two European Position Papers in Rhinosinusitis and Nasal Polyposis (EP3OS) documents, published in 2005 and 2007, respectively. The latter is intended to be a state-of-the art review for specialists and general practitioners, updating the current knowledge on rhinosinusitis and nasal polyposis, proposing the guidance for definitions and outcome measurements in research and providing an evidence-based review of the available treatments. The present article briefly discusses the guidelines for acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) diagnoses, as well as treatment recommendations provided by that document. Recent, epidemiological PROSINUS study of ARS, carried out in Spain, is also briefly reviewed, with special emphasis on Cyclamen europaeum extract use in ARS treatment. A new treatment approach is proposed, based on Cyclamen europaeum extract use in ARS and in the postoperative management of patients with CRS and nasal polyps undergoing endoscopic sinus surgery, which is associated with clinically confirmed, significant improvement of patients' symptoms, nasal endoscopic signs and patient satisfaction in comparison to saline. These results are thought to be connected with nasal drainage-facilitating and paranasal sinuses-cleaning activities of the extract.

Murine complement deficiency ameliorates acute cigarette smoke-induced nasal damage

OBJECTIVE

Exposure to cigarette smoke is a risk factor for chronic rhinosinusitis. Current literature confirms complement fragments are activated in human nasal mucosa. The mechanism(s) responsible for this activation is unclear. We investigated the effects of cigarette smoke on nasal mucosa in vitro and via a model of cigarette smoke exposure by using animals deficient in complement components.

STUDY DESIGN

Prospective, controlled animal and in vitro human cell line study.

SETTING

University laboratory.

SUBJECTS AND METHODS

Human respiratory epithelial cells were exposed to five, 10, and 20 percent cigarette smoke extract (CSE) in vitro in the presence or absence of human serum. Complement activation was assessed by enzyme-linked immunosorbent assay and immunofluorescent techniques. Complement-deficient (C3(-/-), n = 6; factor B(-/-), n = 50) and sufficient mice (wild type, n = 10) were exposed to the smoke of four cigarettes per exposure for two exposures per day for three days. Mice were sacrificed 12 hours after the last exposure, and the nasal cavity was surgically removed. Histological characteristics were analyzed by the use of a subjective scale and quantitative image analysis scoring systems.

RESULTS

In vitro analysis of respiratory cell cultures demonstrated that exposure of serum to CSE resulted in complement activation. Furthermore, immunofluorescent staining for C3d could only be demonstrated in CSE-exposed cultures. In vivo analysis demonstrated that complement deficiency, either C3 or factor B deficiency, resulted in a significant reduction in histological evidence of damage as compared with wild-type control mice (wild type vs C3(-/-), P = 0.02; wild type vs factor B(-/-), P = 0.07; no significant difference between C3(-/-) vs factor B(-/-)).

CONCLUSION

These data demonstrate that cigarette smoke activates the complement system. Furthermore, complement deficiency protected against smoke-induced mucosal damage in this small series.

Fungus: a role in pathophysiology of chronic rhinosinusitis, disease modifier, a treatment target, or no role at all?

Fungal spores, due to their ubiquitous nature, are continuously inhaled and deposited on the airway mucosa. This article focuses on the potential role of fungi in chronic rhinosinusitis (CRS). Five forms of fungal disease affecting the nose and paranasal sinuses have been recognized: (1) acute invasive fungal rhinosinusitis (including rhinocerebral mucormycosis), (2) chronic invasive fungal rhinosinusitis, (3) granulomatous invasive fungal rhinosinusitis, (4) fungal ball (mycetoma), and (5) noninvasive (allergic) fungal rhinosinusitis. There are several potential deficits in the innate and potentially also acquired immunity of CRS patients that might reduce or change their ability to react to fungi. There are not many arguments to suggest a causative role for fungi in CRS with or without nasal polyps. However, due to the intrinsic or induced change in immunity of CRS patients, fungi might have a disease-modifying role.

Inflammatory diseases of the nasal cavities and paranasal sinuses

Inflammatory diseases of the nose and paranasal sinus are commonly encountered in diagnostic histopathology. This review describes the possible manifestations of the common diseases as well as highlighting some of the uncommon causes of sinonasal inflammation which may have importance for treatment and prognosis. The diagnosis of fungal sinusitis is primarily histological. It is important to distinguish between invasive and non-invasive fungal sinusitis, the latter including allergic fungal sinusitis characterized by 'allergic mucin' and scanty fungal hyphae. Nasal eosinophilia is a feature of both allergic and non-allergic rhinosinusitis and a wide range of secondary changes in inflammatory polyps may lead to diagnostic confusion. Nasal biopsies are often taken from perforations or inflammatory masses to confirm or exclude granulomatous diseases. There is a broad differential diagnosis for granulomatous sinonasal disease and pathologists should appreciate the diagnostic histological and clinical features of these conditions.

[GA2LEN (Global Allergy and Asthma European Network), the perspective of the German speaking centers]

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle allergy as a whole. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.

Methotrexate: can it be a choice for nasal polyposis in aspirin exacerbated respiratory disease?

Nasal polyposis (NP) is considered a subgroup of chronic rhinosinusitis and is commonly associated with asthma, bronchiectasis, and cystic fibrosis. A certain subgroup of nasal polyposis is known as Aspirin Exacerbated Respiratory Disease (AERD), previously called Samter's Triad or aspirin triad, comprising polyposis, asthma, and aspirin hypersensitivity and makes up almost 10% of cases of NP. Therapy of NP involves a combination of medical and surgical treatments. However, recurrences are common, particularly in patients with asthma and aspirin hypersensitivity. Both topical and systemic corticosteroids form the mainstay of conservative therapy for NP as well as a primary treatment and prevention for recurrences. They have been shown to improve nasal breathing, rhinitis symptoms, and reduce the size of NP, along with the rate of recurrence. There is great concern about the adverse effects of systemic steroids, especially when long-term usage is necessary to maintain improvement. So far, no knowledge exists about the effects of methotrexate (MTX) on NP of the patients with asthma. We report two patients whose NP dramatically reduced in size after a course of MTX therapy administered as an additional treatment for their steroid- dependent asthma.

[GA2LEN (Global Allergy and Asthma European Network)]

Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle Allergy in its globality. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.